Sputtering with Mach 4 Injectors

C

ctd2001

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Oct 22, 2006
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Installed some F1 Mach 4 injectors in a 02 4x4 6spd with a FASS pump and a diablo power puck. Truck starts easy and idles smooth, the problem is when you get on it sputter/ breaks up and is not so smooth. I removed the power puck and drove the truck and it was smooth excelerating through all the gears and never sputtered once. It seems to me like a timing issue but I'm not sure how to correct it other then removing the puck and installing a boost fooler. Any input would be great, thanks
 
Temp????

Cold there? My Mach 6 sticks do the same in cold weather. Trying Mach 7 sticks tomorrow.
 
Ya it is cold, high of 40 today, I thought the same thing as well. I put some cardboard in front of the radiator to run it a bit warmer to see if that would smooth it out some, but didn't seem to help much. I'm wondering if it's worth cleaning the IAT sensor
 
How does it do with the puck and when accelerating with the cruise control instead of the pedal?
 
Haven't tried that but will give it a shot, are you thinking possible erratic APPS?
 
Used the cruise control button to accelerate going down the highway tonight and it was smooth with no sputtering. Do you have any thoughts about what be happening? Could it be seeing erratic voltage from the Apps when accelerating hard using the pedal?? Thanks
 
Yes. It seems to be amplified by chips and boxes too. How to resolve the issue? I wish I knew.
A new Timbo APPS, didn't help.
Replacing the IAT didn't either.
On two occasions, relocating conductors around the OEM harness helped (sort of), but it really wasn't a complete solution.

There's a shield that is supposed to drain the noise; however, it "seems" to be what doesn't work, where the PCM has an on board filter on the signal circuit. That does work.
I was thinking of taking the harness apart and wrapping the twisted conductors for the APPS with a foil shield that is connected at the battery on one end and to the ECM / Engine ground at the other. A tedious job and it may not even work. Perhaps a pi filter at the ECM?

Hopefully, someone has figured out a simple solution to keep this noise out of the ECM.
 
I agree that is deff some kind of electrical noise that causes the issue and not any fault of the injector. What conductors are you referring to and how did you relocate them? I'm sure the electrical noise has always been present, it's just becomes noticeable with a larger injector. Thanks
 
There were to installs where folks had installed H.I.D. ballasta on the firewall to keep the clean an dry, then run they ran the cable from the ballast to the lights along the driver's side and zip tied it to the harness. In that case, I moved their ballasts back to the firewall so the lighting circuit was no longer near the harness between the APPS and the ECM. The other time was an electric fuel pump located on the frame near where the vacuum solenoid is located for the older cruise controls and the conductors from the plug at the back of the engine were zip tied to the wiring harness. Both times the folks did a nice looking job and were really trying for a clean install, but the circuit routes caused additional noise to be induced onto the APPS twisted pair.

Additonally, a pi filter would not be correct. A simple capacitor filter would probably be a better solution to keep from attenuating the signal voltage. I don't recall which pins at the ECM are which, but I can look them up if you're interested.

Even though the ECM looks at the difference in voltage between the two conductors when not on the idle circuit, I've been tempted to go ahead and tie both together near the ECM and run a single large capacitor for both instead of one per conductor.

I keep hoping someone will already know the answer and I can just implement it instead of having to take the time to really figure it out.....how lazy is that!?!
 
Well if you were able to figure it out then you could be the one to take all the credit and maybe even start selling a fix solution for the problem. So I think what your saying is that you believe these chips/boxes are sending off dirty electrical noise that is not being contained and that this dirty noise is being picked up by the wires from the ECM to the apps. If that's the case can the boxes/chips be better shielded so that this noise is being contained? I know what you mean about this HID ballast, every time I turn my lights on, my TST remote lights up even when I have the unit powered off.
 
No, I don't believe the boxes are creating noise. I do believe they make the circuits more sensitive so any noise that is there becomes very noticeable.

Have you checked the resistance from:
(1) the negative battery post at the driver's side to the body ground at the radiator support?
(2) the ECM to the negative battery post at the driver's side battery?

I checked one rig and it was 2 ohms even after cleaning the battery terminal and grounding locations on the radiator support! I'm curious what yours is.
 
Pulled the Timbo pigtail last weekend and put a (470microFarad capacitor across pins 3 - green wire (positive side of cap) and 4 - black wire (negative side of cap). That size was used because it's what I had and short of using equipment I don't have like an Oscilloscope, I had to guess where to start.

All of the bucking and snorting around is gone while maintaining speed, normal acceleration and moderate acceleration. Under heavy acceleration, it will still buck a little. A larger capacitor will be in order. I'm also concerned about the capacitor staying charged and a spike taking out part of the ECM, so a very large drain resistor will find it's way into the circuit also.

So, this is promising, but not the final effort to filter out noise on the signal circuit from the APPS to the ECM.
 
I just turn my box off for winter. My truck will shake and buck under moderate to heavy throttle in anything under 50*.
 
What about installing a ferrite bead? Make a couple loops through it, it effectively removes most all electrical noise, also known as a choke or reactor.
 
Good work Rob. Would a largish capacitor also delay returning to idle slightly if you lift off quickly (maybe it would have a side benefit of helping reduce or eliminate turbo bark).
 
crackerman said:
What about installing a ferrite bead? Make a couple loops through it, it effectively removes most all electrical noise, also known as a choke or reactor.
Click to expand...

I have one, but opted to go the capacitor filter route so I didn't have to lengthen any of the existing conductors to wrap around the choke. It was either TST or Blue Chip that used to include a choke with their box. Maybe they still do. IMHO, to really work very well, it would have to be grounded to the negative side of the battery. If I can really get some time to do this right, I'll also try the choke just so we'll know.
 
VMacKenzie said:
Good work Rob. Would a largish capacitor also delay returning to idle slightly if you lift off quickly (maybe it would have a side benefit of helping reduce or eliminate turbo bark).
Click to expand...

Hi Vaughn,
Yes, it will "technically" slow the drop in voltage a little, but for all practical purposes it won't make any difference. Without measuring the resistance of the circuit looking back toward the ECM and toward the APPS, I can only guess that worst case would be the reactance of the capacitor alone. I doubt the millisecond delay will keep a turbo from barking or keep the VP from pulling air with larger injectors.

Again, I'm only guessing, but on the later second gens (01.5 and 02), I believe that once the idle circuit "on", that it won't matter what the voltage is on the rheostat (off idle) circuit.

Didn't you install a 3rd gen variable vane turbo of some flavor? Is it barking?
 
The pickup was in the garage so I could swap out the compressor housing on the secondary turbo, so I also up sized the capacitor. It went from a 35V 470uF to 35V 1000uF located at the APPS. No significant improvement over the 470uF cap was noticed. The remaining noise will have to be filtered out at the ECM, so next will be to add another 1000uF at the ECM next time it's in the garage.
 
i think im getting same issue....except mine feels more like a surging, rather than a random bucking/sputtering. it feels like the power is on and off and on and off, pulsating would be a good work for it i spose.
 
Will be interesting to see what happens when you add a filter at the ECM Rob. Also out of curiousity have you tried any of the other noise suppression techniques others have tried, such as splicing into the ground wire of the APPS harness and grounding to the dash, or the Navone filter (bulky) which I think goes to the PCM? Also in one TDR issue it talked about taking a wire from the alternator which runs through a wire harness and rerouting it or running a replacement by itself as a solution but the article wasn't clear on which wire that was.

My '98.5 doesn't have any of the TC lockup issues but it has a funny surging romp that happens at steady cruising around 30-45 MPH in Drive within the first 2-3 miles after starting the truck.

As for the question about the 3G turbo I had that on my last truck, I have a Garrett on my '98.5 and I don't have problems with barking, it was a theoretical thought more than anything. It would make sense the ECM would ignore any voltage if idle validation is present.
 
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